Polarizing device integrated with touch sensor

ABSTRACT

A polarizing device has a polarizing layer, a first protection layer, a second protection layer, a conductive layer, an insulating layer, an electrode layer and a hardening coating layer. When a user touches a monitor, which is implemented with the polarizing device, by his/her finger, the coordinate of the touch point will be detected by monitoring the interference caused on the equivalently generated electric filed.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a touch sensor capable ofpolarizing a light beam for being employed in a LCD (Liquid CrystalDisplay) panel or monitor.

[0003] 2. Background Description

[0004] In the present technologies for concerning the convenience andfriendship, the user interface is developed to implement ordinary userhabits. Thus, users may manipulate the technology products via aninteractive human interface, rather than learning lots knowledge andcomputer instructions, such for computers, home appliances, guidingsystems (G.P.S. or others) and personal digital assistance (PDA). Thescreens of high technology products are able to be clicked in order toinput the instructions directly via screens, so-called touch screens.Thus, the user friendly interface is enhanced from ordinary inputdevices such as mouses or keyboards.

[0005] The touch screens as aforementioned, as shown in FIG. 1, includesa glass substrate 10, a first conductive layer 11, a first insulationlayer 12, a first electrode layer 13, an isolation layer 14, a secondelectrode layer 15, a second insulation layer 16, a second insulationlayer 17 and a film 18. The first conductive layer 11 and the secondconductive layer 17 are conductive materials, for example Indium TinOxide (ITO). The first conducted layer 11 is sputtered to the glasssubstrate 10. The second conductive layer 17 is also sputtered to thefilm 18. In this case, both the glass substrate 10 and the film 18 areconductive. After that, the first insulation layer 12 and the secondinsulation layer 16 are printed to the glass substrate 10 and the film18 respectively. The first conductive layer 12 and the second conductivelayer 16 are designated to spread equipotential voltage filed over theconductive layers. The first electrode layer 13 and the second electrodelayer 15 are made by conductive material, such as silver paste. Thefirst electrode layer 13 and the second electrode layer 15 are printedto the first conductive layer 11 and the second conductive layer 17respectively. A first electrode 131 and a second electrode 132 of thefirst electrode layer 13 are positioned in parallel. A third electrode151 and a fourth electrode 152 of the second electrode 15 are alsopositioned in parallel. The electrode leads 133, 134, 153 and 154 areconnected to the first electrode 131, the second electrode 132, thethird electrode 153 and the fourth electrode 154 respectively forpropagating signals. Once the isolation layer 14 is printed on the firstconductive layer 11, a touch screen is completed after combining theglass substrate and the film by an adhesive material.

[0006] Please refer to FIG. 2A, the figure shows the cross section alongline A-A′, especially under the condition that the user does not pressdown the film or the user does not click on the screen. There is anisolation layer between the first conductive layer 11 and the secondconductive layer 17. The isolation layer 14 contains plurality ofspacers 140 in order to prevent the contacts between the firstconductive layer 11 and the second conductive layer 17. If the firstconductive layer 11 and the second conductive layer 17 are notcontacted, there will be no signal generated and outputted. Further inview of FIG. 2B, if the user presses down or click on the film 18 byuser's finger 20, the film 18 will be bent. Thus, the second conductivelayer 17 is bent to contact the first conductive layer 11. Since thefirst electrode 131 is provided a five voltage (5V) via the electrodelead 133 and the second electrode 132 is provided a zero voltage (0V)via the electrode lead 134, there is voltage gap of five voltage (5V)between the first electrode 131 and the second electrode 132. In thiscase, a general and equivalent equipotential filed from 0V to 5V isgenerated. If the second conductive layer 17 is bent to contact thefirst conductive layer 11, the coordinates of the contact point 21 willbe recognized by sampling out the voltage signal. The voltage presentsthe one axis position of the coordinate of the contact point 21, such asthe position along X-axis. After a predetermined time shift, anequipotential filed is generated between the third electrode 151 and thefourth electrode 152. By sampling out the voltage signal of the contactpoint, the position of the coordinate of the contact point is acquiredalong the Y-axis as shown in FIG. 1. By switching the two equipotentialfields on the first conductive layer 13 and the second conductive layer15, the coordinates of the movement of the finger on the film 18 will beacquired. Accordingly, the touch sensor 1 is required to be integratedwith a display (usually a liquid crystal display). In this case, theuser may see the content of the display in order to touch the touchsensor to input the instruction.

[0007] In an ordinary liquid crystal display, there is implemented apolarizer for polarizing a light beam with a specific polarity. FIG. 3Ashows the structure of the polarizer 2. The polarizer 2 comprises apolarizing layer 20, a first protection layer 22 and a second protectionlayer 24. The polarizing layer 20 is a PVA (Poly Vinyl Alcohol). Thecharacteristic of the PVA is to allow a light beam with a specificpolarity to pass. The first protection layer 22 is positioned in theupper side of the polarizing layer 20, made by the material of PET orother insulating materials. The second protection layer 24 is positionedbelow the polarizing layer 20, made by the material of PET or otherinsulating materials for protecting the polarizing layer 20. Moreover,the first protection layer 22 and the second protection layer 24 arealso for preventing any bending causes to the polarizing layer 20.

[0008] Regarding the cost of the manufactures, Minoura et al. havedisclosed a way to combine the touch sensor 1 and polarizer 2 together.See U.S. Pat. No. 6,108,064. Minoura et al. taught to integrate thetouch sensor 1 and the polarizer 2 by adhesive. As shown in FIG. 3B, thetouch sensor 1 sticks to the polarizer 2 by adhesive. Thus, the liquidcrystal display (not shown in FIG. 3B) employing the polarizer 2 iscapable of touch features.

[0009] However, this kind of manufacturing processes require lotsalignment procedures. Further, to paste the adhesive over either thetouch sensor 1 or the polarizer 2 will easily leave some adhesive on thetouch sensor 1 or the polarizer 2, which causes lots rejected productsalong with other defected issues. In this case, the present inventionprovides an integrated touch sensor or called an integrated polarizerfor reducing the aforementioned problems.

SUMMARY OF THE INVENTION

[0010] It is therefore an object of the present invention to provide apolarizing device integrated with a touch sensor. So that the polarizingdevice is capable of touch features.

[0011] It is another object of the present invention to provide alow-cost device to be implemented to the liquid crystal display.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The foregoing and other objects, aspects and advantages will bebetter understood from the following detailed description of a preferredembodiment of the invention with reference to the drawings, in which:

[0013]FIG. 1 is the schematic exploded view of the prior known touchsensor;

[0014]FIG. 2A shows the cross section of the prior known touch sensor;

[0015]FIG. 2B shows the prior known touch sensor being pressed down;

[0016]FIG. 3A is the schematic exploded view of the prior knownpolarizing device;

[0017]FIG. 3B show the adhesive combination of the prior known touchsensor and the prior known polarizing;

[0018]FIG. 4A shows the exploded view of the first embodiment of thepresent invention;

[0019]FIG. 4B shows the electrode layer of the first embodiment of thepresent invention;

[0020]FIG. 5 is the exploded view of the second embodiment of thepresent invention; and

[0021]FIG. 6 shows the exploded view of the third embodiment of thepresent invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

[0022] Please refer to FIG. 4A, this drawing shows the exploded view ofthe first embodiment of the present invention. The polarizing device 4includes a polarizing layer 40, a first protection layer 42 and a secondprotection layer 44. The touch sensing device 5 includes a conductivelayer 51, an insulating layer 52, an electrode layer 53 and a hardeningcoating layer 55. The conductive layer 51 is made of conductivematerial, for example ITO (Indium Tin Oxide). The conductive layer 51 issputtered to the first protection layer 42. In this case, the protectionlayer 42 is able to propagate the electric filed over the surface. Theinsulating layer is printed to the conductive layer 51. Since theinsulating layer 52 is rectangular shape, it would limit the electricdistribution over the conductive layer 51. The insulating layer may alsobe conducted by laser etching to do the same effects, especially to theoutside perimeter. Further, the electrode layer 53, composition ofsilver, is printed to the conductive layer 51. The arrangement of theelectrodes may be presented as the shape shown in FIG. 4B as such thefirst electrode 531, the second electrode 532, the third electrode 533and the fourth electrode 534. The four electrodes 531, 532, 533 and 534are along each side of the conductive layer 51. The electrodes 531, 532,533 and 534 connect to electrode leads 535, 536, 537 and 538respectively. An equally spread equipotential electric field isgenerated between the first electrode 531 and the second electrode 532.The electrical field represents the coordinate of X-direction. Theequipotential field between the electrode 533 and the electrode 534 mayalso represent the coordinate of Y-direction. At last, the hardeningcoating layer 55 is adherent to the electrode layer 53, made bynon-conductive hardening materials for protecting the conductive layer53 or the electrode layer 55 not being scratched or damaged.

[0023] Further details of the fist embodiment of the present inventionis illustrated as the followings. When the finger of a user touches thescreen or moves close the screen. The electric field between the firstelectrode 531 and the second electrode 532 will be interfered. The sizeor the shape or interference type may be detected and monitored by theelectrode lead 535. In this case, the coordinate of the X-axis may berecognized. After a very short predetermined time period, the electricfield will be shifted and generated between the third electrode 533 andthe fourth electrode 534. The electric field is also interfered by thefinger. Thus, the coordinate of the Y-axis will be detected bymonitoring the electrode lead 536. In view of the above demonstration,the integrated polarizing device is capable of touch features and ableto cost down during the manufacturing processes, compared to anindependent touch sensor and an independent polarizing device.

[0024]FIG. 5 shows the second embodiment of the present invention. Thedifference between the first embodiment and the second embodiment isthat the conductive layer 51 is sputtered over the polarizing layer 40of the polarizing device 5. The insulating layer 52 and the electrodelayer 53 are printed on the conductive layer in sequence. Finally, thefirst protection layer 42 substitutes the hardening coating layer 55 ofthe first embodiment for protecting the conductive layer 53.

[0025] The first protection layer 42 may be made by PET material orother non-conductive materials. The hardness of the first protectionlayer 42 must be enough to protect the conductive layer 53 for avoidingscratches. In this case, the structure, even the manufacturingprocesses, is simplified.

[0026]FIG. 6 shows the third embodiment of the present invention. Thedifference between the first embodiment and the second embodiment isthat a second conductive layer 64 is added. The first conductive 61 andthe second conductive layer 64 are spluttered to both side of the firstprotection layer 42. Further the insulating layer 62, the electrodelayer 63 and the hardening coating layer 65 are adherent as shown in thefirst embodiment of the present invention. Two pairs of opposingelectrodes (electrodes 631, 632, 633 and 634) are positioned at foursides of the first conductive layer 61. Each electrode contains anelectrode lead (for instance, the electrode leads 635, 636, 637 and638). By supplying a 5V to the electrode 631 via the electrode lead 635and supplying a 0V to the electrode 632 via the electrode lead 636, anequivalent electric filed (0V to 5V) is generated over the firstconductive. Meanwhile, the second conductive layer is supplied anelectrical filed. In this case, capacity effects is generated betweenthe two electric fields. When the user touches the screen, the capacityis interfered. Thus, the coordinate along X-axis is detected bymonitoring the output of the electrode lead 635. After a very short timeperiod, by providing 5V and 0V voltages to the electrodes 633 and 634respectively, the capacity interference caused by finger or otherobjects will help to find the coordinate along Y-axis.

[0027] The aforementioned three embodiments integrate the touch featureof an ordinary touch sensor to a polarizing device. By the presentinvention, the cost is reduced and the integrated product is thereforeobtained. At the post assembling processes, the manufacturer does notneed to assemble the polarizing device firstly to an unfinished liquidcrystal module then attaching an independent touch sensor.

[0028] Although preferred embodiments of the present invention have beendescribed in the forgoing description and illustrated in theaccompanying drawings, it will be understood that the invention is notlimited to the embodiments disclosed, but is capable of numerousrearrangements, modifications, and substituting of parts and elementswithout departing from the spirit and scope of the invention.Accordingly, the present invention is intended to encompass suchrearrangements, modifications, and substitutions of parts and elementsas fall within the scope of the appended claims.

1. A polarizing device integrated with a touch sensor comprising: apolarizing layer; a first protection layer, positioned on saidpolarizing layer, made by non-conductive materials; a conductive layer,tightly integrated with said first protection layer; an electrode layerfor propagating electrical signals; and a hardening coating layer,positioned on the electrode layer, made by non-conductive material,wherein electrodes of said electrode layer generates a steady electricalfield over said conductive layer.
 2. The polarizing device of claim 1,further comprising: a second protection layer, positioned on the bottomside of said conductive layer.
 3. The polarizing device of claim 1,wherein said conductive layer is sputtered on said first protectionlayer.
 4. The polarizing device of claim 1, wherein said firstprotection layer protects said polarizing layer from scratches.
 5. Thepolarizing device of claim 1, wherein said electrode layer is printed onsaid conductive layer.
 6. The polarizing device of claim 1, wherein saidelectrode layer contains at lease two pairs of said electrodes, eachelectrode having an electrode lead respectively.
 7. The polarizingdevice of claim 1, further comprising an insulating layer, placed inbetween said conductive layer and said electrode layer.
 8. Thepolarizing device of claim 1, wherein the perimeter of said conductivelayer is etched to cause insulating effects.
 9. The polarizing device ofclaim 1, wherein the perimeter of said conductive layer is eliminated tocause insulating effects by laser cuts.
 10. A polarizing deviceintegrated with a touch sensor comprising: a polarizing layer, withcompos ition of the material of poly vinyl alcohol (PVA); a conductivelayer, tightly integrated with said polarizing layer; an electrode layerfor propagating electrical signals; and a first protection layer,positioned on said electrode layer, made by non-conductive material,wherein electrodes of said electrode layer generates a steady electricalfield over said conductive layer.
 11. The polarizing device of claim 10,further comprising: a second protection layer, positioned on the bottomside of said polarizing layer, made by non-conductive materials.
 12. Thepolarizing device of claim 10, wherein said conductive layer issputtered on said polarizing layer.
 13. A polarizing device integratedwith a touch sensor, comprising: a polarizing layer; a first protectionlayer, positioned on said polarizing layer, made by non-conductivematerials; a first conductive layer, tightly integrated with said firstprotection layer; a second conductive layer, tightly integrated withsaid polarizing layer; an electrode layer for propagating electricalsignals; and a hardening coating layer, positioned on the electrodelayer, made by non-conductive materials, for avoiding scratches ordamages, wherein electrodes of said electrode layer generates a steadyelectrical field over said conductive layer.
 14. The polarizing deviceof claim 13, further comprising: a second protection layer, positionedon the bottom side to said polarizing layer, made by non-conductivematerials.
 15. The polarizing device of claim 13, further comprising: aninsulating layer, placed in between said conductive layer and saidelectrode layer.
 16. The polarizing device of claim 13, wherein theperimeter of said conductive layer is etched to cause insulatingeffects.
 17. The polarizing device of claim 13, wherein the perimeter ofsaid conductive layer is eliminated to cause insulating effects by lasercuts.
 18. The polarizing device of claim 13, wherein said electrodelayer contains at lease two pairs of said electrodes, each electrodehaving an electrode lead respectively.